The present invention relates to electric power generation and more particularly to systems and methods for operating the inlet valves of steam turbines in such plants with improved reliability and better protection.
In the operation of electric power plant steam turbines such as large steam turbines which have multiple throttle and multiple governor inlet valves, the availability of the turbine to drive its generator for electric power production and the accuracy of turbine operation during turbine availability depend in part on the proper functioning of the steam valves and their controls. Throttle valve tests have been employed for periodic checking of throttle valve performance during turbine load operation when the throttle valves are normally wide open. Since large turbines are operated in the load mode most of the time, adjustments in governor valve positions for load changes have served as a check on governor valve operation without special testing. More continuous valve performance evaluation is desirable in order to provide better protection against turbine operating bumps which may occur during valve changes or valve control changes because of faulty valve operation or control and further to provide better plant availability and reliability as a result of the detecting of faulty conditions at a time when protective action can be taken without seriously affecting the plant operation.